DES MOINES, Iowa - The unexpected discovery of a species of sunfish not seen in Iowa in more than 80 years has fisheries biologists perplexed and excited.
While collecting fish for an educational program in June, Iowa Department of Natural Resources fisheries technician Adam Thiese netted what appears to be a longear sunfish, the first one identified in Iowa waters since 1932.
The fish was taken from one of the ponds at the Fairport Fish Hatchery, located on the Mississippi River at Muscatine. The hatchery has 18 ponds used to hatch and raise warm-water fish including largemouth bass and bluegill. The ponds are occasionally drained and the fish gathered for distribution to Iowa's interior rivers and ponds.
As staff members drained one of the ponds Wednesday, two more fish believed to be male longear sunfish were found.
"There's quite a bit of excitement about it," Thiese said. "It's a fish we haven't documented in Iowa here since 1932 so as far as distribution of the longear sunfish it's a pretty big deal. As far as Iowa fisheries goes it's a pretty big deal."
Before the recent discovery, the last longear sunfish documented in Iowa was on the Cedar River near Otranto, a small unincorporated community near St. Ansgar
Fin clippings of the Muscatine fish will be sent to a laboratory for DNA testing to confirm the species.
Longears usually are from 5 inches to 7 inches long and weigh up to 4 1/2 ounces.
"The longear sunfish is one of the most beautiful freshwater fish there are," said Keith Bryant Gido, a biology professor at Kansas State University who specializes in fish ecology and habitat. "The breeding male is just spectacular. They get this awesome orange crest on the back of their necks. It's just a fantastic species."
It's not clear yet why the fish suddenly have reappeared in Iowa.
Thiese said one theory is that recent Mississippi River flooding, which pushed high water up into the ponds, may have carried a small population of the fish that could have been living in small creeks and streams along the river.
"It's interesting in Iowa there historically was a small population that disappeared," Gido said. "When you lose one obviously something has changed. They're a good indicator or barometer of that change."
It's also possible someone may have caught one somewhere and brought them into Iowa, or they could have been living in such low numbers they were overlooked in sampling, Gido said.
Longear sunfish tend to favor streams with moving water unlike similar species, including the green sunfish or the bluegill, which live comfortably in standing water.
While records dating to the 1890s show longears in some of the state's interior streams, the population in Iowa appears to never have been large, Thiese said.
Elsewhere they are common, Gido said. They're caught frequently where he lives in Manhattan, Kansas, he said.
A U.S. Geological Survey map shows the species common in states to the east and south of Iowa, including Illinois and Missouri. They are known in the Great Lakes area, the Mississippi River, west of the Appalachian Mountain and into Texas, Louisiana, Mississippi and Alabama.
For now the three known Iowa longear sunfish are living in an aquarium at the hatchery in Muscatine while fish experts study their sudden reappearance and what it might mean.